As known, helmets serve to protect the head of the user against impacts and knocks that may occur during sports activities, such as for example car racing, motorcycle racing, skiing, etc. or the so-called civil interventions, like in the case of fire fighters, health workers on ambulances etc, wherein the mechanical and functional resistance characteristics must meet the required standards for the respective approval.
In the current helmets it is known to provide for modular construction methods which allow the application or removal of parts or components of the helmet. Examples of execution of helmets of the prior art are observable for example from various documents.
Document WO2010149878 A1 discloses an interchangeable external cap, in particular for motorcycle helmets, wherein said external cap is made up of two parts fixed to each other, one of which, i.e. the main cap absorbs and reduces effects in case of a fall and impact, while the second which is in the nape area is only designed for aesthetic purposes and helmet graphic customisation.
Document EP0931467A3 discloses a helmet with a separable external cap provided with through ventilation openings over an internal cap of the helmet, equally provided with cavities for ventilation purposes, for example for cyclists, wherein said caps are equally designed for helmet customisation.
Document EP2229830 B1 illustrates a helmet having a separable external cap, which constitutes an aesthetic and non-structural cap, thus especially made for aesthetic graphic helmet customisation purposes.
Document US2003070200 A1 discloses a ballistic military helmet, in which the base is a ballistic cap to which there are internally applied comfort linings, while the external has a cover made of camouflage fabric or the like.
Document WO2013057745 A1 discloses a multifunctional public order protection helmet, whose distinctive characteristic lies in the integrated arrangement of a Bluetooth sound system.
Document U.S. Pat. No. 6,282,726 B1 illustrates a fire fighter helmet in which there are provided two visors which rotate internally and are hinged concentrically.
In the known helmets there are provided separable parts, displaceable or integrated for customisation purposes or improving the use conditions helmets, but which do not regard parts modifying the protection level of the helmet.
It is observed that in military applications the so-called ballistic helmet was conceived for protecting the head of the user against direct and indirect impacts of bullets or fragments thereof.
The inventor observed that in the aeronautic industry, and in particular helicopter operators, the personnel uses helmets without any type of ballistic protection, made of plastic or composite material and solely aimed at providing protection against accidental impacts and incorporate an inter-sound communication system with a high soundproof degree.
In addition, it is known that the new operating interventions that are to be carried out with aircrafts have required the use of ballistic protections both for the transported personnel and especially for the crew actively taking part in the missions.
Currently, ballistic elements are exclusively used by ground personnel, and cannot be used for aeronautic purposes, due to the fact that these helmets, due to their weight, design and soundproof ability, are not applicable to aircrafts.
In addition, it is known that the current ballistic helmets, made using high resistance fibres such as DYNEMA, KEVLAR, etc. have relatively short life/use cycles (having a not more than 5-year expiry) hence the administrations managing these ballistic helmets have to constantly request them hence implying high costs.
A further disadvantage of the current helmets lies in the fact that they are not adaptable in their protection level to the type of threat to be expected and thus not lead to the user carrying the weight on the head even when not necessary.